PANCREATIC ENZYMES Flashcards

1
Q

PANCREATIC ENZYMES
These enzymes are:

A

• AMYLASE
• LIPASE

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2
Q

The pancreas does not only produce amylase and lipase, it also produces many other enzymes such as,

A

elastase
trypsin
pepsin

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3
Q

We ONLY test for AMYLASE and LIPASE to diagnose…

A

ACUTE PANCREATITIS

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4
Q

Endocrine = HORMONES from______.

Exits to the_______.

A

Pancreatic Islets

Bloodstream

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5
Q

Exocrine = Mainly ENZYMES from_____

Exits through the_____

A

Acinar cells

Pancreatic duct

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6
Q

Amylase

EC

A

E.C 3.2.1.1

1,4-D-Glucan Glucanohydrolase

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7
Q

AMS

Breakdown of______ to monosaccharides

A

starch and glycogen

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8
Q

AMS

Activators:

A

CALCIUM and CHLORIDE

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9
Q

Amylase follows the____ specificity; they are bound to react with structures with____

A

LINKAGE

a-1,4-glycosidic bonds.

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10
Q

The type of amylase that is present in humans is_____

______is found in plants and microorganisms

A

ALPHA (a)

Beta (B)

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11
Q

TISSUE SOURCES OF AMS

A

SALIVARY GLANDS

ACINAR CELLS OF THE PANCREAS

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12
Q

Salivary amylase also known as

A

Ptyalin

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13
Q

Pancreatic amylase also known as

A

Amylopsin

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14
Q

The fact also that the amylase has 2 major sources makes the amylase_____

• If the patient has increased amylase concentration then you can narrow it down to___ organs.

A

NON-SPECIFIC

2

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15
Q

MW od Amylase

A

50,000 - 55,000 MW

that why it is easily filtered from the circulation

SMALLEST ENZYME

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16
Q

Readily filtered by the glomerulus due to its small molecular weight.

Once inside the glomerulus it is NOT REABSORBED by the tubules.

A

Amylase

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17
Q

T or F

We can detect amylase in the urine

A

True

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18
Q
  • initial digestion of starch by salivary AMS

Inactivated in the stomach. Why?

A

MOUTH

Due to the presence of acid

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19
Q
  • final digestion by pancreatic AMS
A

SMALL INTESTINE

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20
Q

ISOENZYMES OF AMS

A

P-type isoamylase
S-type isoamylase

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21
Q

Pancreas
P3: Predominant in AP

A

• P-type isoamylase

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22
Q

Salivary gland
Lungs (levels not significant)
Fallopian tubes (levels not significant)

A

S-type isoamylase (None pancreas)

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23
Q

____is usually what’s checked when we run a serum sample to check its amylase level content

HIGH____ is indicative of having acute pancreatitis

A

P3

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24
Q

DIAGNOSTIC SIGNIFICANCE of Amylase

A

Acute pancreatitis
Salivary gland lesions
Intra-abdominal diseases

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25
Q

Acute Pancreatitis (AMS)
• Rise:_____ after the onset of an attack

A

5-8 Hrs

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26
Q

Acute Pancreatitis (AMS)

Peak:
Normalize:

A

24 Hrs.

3-5 days

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27
Q

Salivary Gland Lesions

  • disease in parotid glands (Mumps)
A

Parotitis

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28
Q

Acute pancreatitis has 3 possible causes:

A
  1. Duct Obstruction
  2. Acinar Cell Iniurv
  3. Defective Intracellular Transport
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29
Q

Remember that in our pancreas we have proenzymes which acts as a safety net for the pancreas, since proenzymes are inactivated protease, no digestion in itself will happen.

But if the proenzymes are activated WITHIN the pancreas then that would lead to some serious trouble and would cause the pancreas to be digested by its own enzyme.

A

Acute pancreatitis

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30
Q

DUCT OBSTRUCTION
• There is something that OBSTRUCTS the pancreatic duct.

Possible cause of obstruction is…

A

GALLSTONES AND PARASITES

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31
Q

Acute pancreatitis

The obstruction caused by the gallstone causes IMPAIRED BLOOD FLOW.

Thus no oxygen can pass through
No oxygen = NECROSIS
Will also lead to the PREMATURE ACTIVATION of the enzymes.

A

Duct obstruction

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32
Q

Alcohol is also TOXIC to the…

A

Acinar cells

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33
Q

• Can be caused by: Alcohol, Drugs, Trauma, Ischemia and Viruses.
• Which leads to the accidental activation of the enzymes in the pancreas.

A

ACINAR CELL INJURY

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34
Q

• For example trypsinogen. This enzyme should have a different pathway from other enzymes released by the pancreas such as the amylase and lipase.
• If trypsinogen goes to the pathway where amylase and lipase goes then, trypsinogen will be activated into trypsin.
• This is problematic since the trypsinogen was activated within the pancreas itself and will now lead to the digestion of its own cells.

A

DEFECTIVE INTRACELLULAR TRANSPORT

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35
Q

• This is the most common type of Hyperamylasemia
• increased Amylase yet essentially NORMAL

A

MACROAMYLASEMIA

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36
Q

• Persistent increase in serum amvlase is seen without clinical symptoms

A

Macroamylasemia

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37
Q

In these patients, the amylase binds to the______

AMS molecules combine with____

This molecules combined together will now become a big structure

Which cannot be filtered out by the glomerulus.

So it will GO BACK to the blood circulation.

Thus, having increased AMS yet the patient feels normal.

A

Macroamylasemia

ANTIBODIES or IMMUNOGLOBULINS.

IgG or IgA.

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38
Q

ASSAY FOR ENZYME ACTIVITY

AMYLASE

A
  1. Amyloclastic method
  2. Saccharogenic method
  3. Chromogenic method
  4. Continuous monitoring method
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39
Q
  • measures the appearance of reducing sugars products by the hydrolysis of starch

•classic reference method

A

Saccharogenic

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40
Q
  • amylase activity by the following decrease or disappearance or decrease in starch substrate concentration
A

Amyloclastic

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41
Q

•AMS hydrolyzes the starch molecule into smaller units, the iodine is released and a decrease occurs in the initial dark-blue color intensity of the starch-iodine complex.

A

Amyloclastic method

42
Q
  • measures the increasing color from production of product coupled with a dye.
A

Chromogenic

43
Q
  • coupling of several enzyme systems to monitor amylase activity (NADH is produced and measured at 340nm)
A

Continuous monitoring

44
Q

Measures the disappearance of starch substrate

A

AMYLOCLASTIC METHOD

45
Q

AMY acts on starch substrate with attached iodine

Hydrolysis releases iodine

Decrease in dark-blue color intensity of starch-iodine complex

Color decrease proportional to AMY concentration

A

AMYLOCLASTIC METHOD

46
Q

Measures the appearance of the product

A

SACCHAROGENIC METHOD

47
Q

Starch substrate hydrolyzed to constituent carbohydrates

Reducing sugars measured

Concentration proportional to
AMY activity

A

SACCHAROGENIC METHOD

48
Q

Saccharogenic method

Classic reference method, reported in…

A

Somogyi units

49
Q

Starch substrate attached to chromogenic dye forming insoluble dye substrate complex

Hydrolysis produces water-soluble dye-substrate fragments

A

CHROMOGENIC METHOD

50
Q

Increase in color intensity of soluble dye-substrate solution

Color intensity proportional to AMY activity

A

Chromogenic method

51
Q

CONTINUOUS-MONITORING
METHOD

Change in absorbance of_____ at _____
Optimal pH for AMY activity:____

A

NAD+ at 340 nm measured

6.9

52
Q

SOURCES OF ERRORS
AMYLASE (AMY)

A

Stability of AMY (in serum and urine)

Inhibitors (Falsely Low AMS)

Medications

53
Q

AMYLASE

Stability of AMY (in serum and urine)
Stable at room temperature for____
Stable at 4°C for____

A

1 week

2 months

54
Q

AMYLASE

• Inhibitors (Falsely Low AMS):

A

• ^ Plasma triglycerides
• Wheat germ lectin
• Chelating agents (EDTA, Citrate, Oxalate)

55
Q

AMYLASE

Medications
(Falsely † AMS):

A

Morphine and Opiates (Pain relief drugs)

56
Q

AMYLASE (AMY)
Specimen handling

Specimen:_______

A

serum or heparinized plasma.

57
Q

AMYLASE

Avoid saliva contamination (____times higher amylase content than serum)

______does not affect most methods except ________involving peroxidase reactions.

A

700

Hemolysis

coupled-enzyme methods

58
Q

AMYLASE

Reference range:
Serum:
Urine:

A

28 to 100 U/L (37°C) (0.5 to 1.7 ukat/L)

1 to 15 U/h

59
Q

NOMENCLATURE of LIPASE (LPS)

A

EC 3.1.1.3
Triacylglycerol acylhydrolase

60
Q

Functions of LIPASE

A

Hydrolyzes ester linkages of fats

Produces alcohols and fatty acids

Targets fatty acid residues at positions 1 and 3 of triglyceride molecule

61
Q

Accelerators of Lipase:

A

colipase and bile salts

62
Q

Hydrolyzes ester linkages of fats

Produces alcohols and fatty acids

Targets fatty acid residues at positions 1 and 3 of triglyceride molecule

A

Lipase

63
Q

LIPASE (LPS)
• Primary Source

• Secondary Sources

A

• Pancreas

• Stomach
• Small intestine

64
Q

• Most specific marker of acute pancreatitis

A

LIPASE (LPS)

65
Q

LIPASE (LPS)
• Comparison with Amylase (AMY)

A

• More specific for pancreatic disorders than AMY
• Both LPS and AMY levels rise quickly
• LPS elevations persist for ~ 8 days
• AMY elevations persist for only 2 to 3 days

66
Q

RISES

AMYLASE
LIPASE

A

5-8hrs
4-8hrs

67
Q

PEAKS

AMYLASE
LIPASE

A

24hrs
24hrs

68
Q

Duration of Elevation

AMYLASE
LIPASE

A

3-5 days
7days

69
Q

Normalize

AMYLASE
LIPASE

A

-
8-14 days

70
Q

ASSAY FOR ENZYME ACTIVITY
LIPASE (LPS)
Early Methods

A

•Classic Cherry-Crandall Method

71
Q

ASSAY FOR ENZYME ACTIVITY
LIPASE (LPS)
Modern Methods

A

• Turbidimetric Methods

• Colorimetric Methods

72
Q

• Used olive oil substrate
• Measured liberated fatty acids by titration
• 24-hour incubation period
• Lacked stable and uniform substrates

A

Classic Cherry-Crandall Method

73
Q

Classic Cherry-Crandall method

• Used _____substrate
• Measured liberated fatty acids by___
•_____incubation period
• Lacked stable and uniform substrates

A

olive oil

titration

24-hour

74
Q

• Modified Cherry Crandall Method: use____ as substrate

A

Triolein

75
Q

Lipase

• Simpler and more rapid
• Fats in solution create a cloudy emulsion
• Hydrolysis by LPS disperses particles
Rate of clearing measures LPS activity

A

Turbidimetric Methods

76
Q

Lipase

• Based on coupled reactions with enzymes (e.g., peroxidase, glycerol kinase)

A

Colorimetric Methods

77
Q

Colorimetric Methods

Examples of enzymes used

A

peroxidase, glycerol kinase

78
Q

SOURCES OF ERRORS
LIPASE (LPS)
• Stability:
Stable in_____

• Negligible loss of activity:
• At room temperature for _____
• At 4°C for_____

A

serum

1 week
3 weeks

79
Q

inhibits LPS activity
Causes falsely low values

A

Hemoglobin

80
Q

SPECIMEN
LIPASE (LPS)

A

Serum/Plasma

81
Q

LIPASE

• Reference range:

A

<38 U/L (37°C) (<0.6 pikat/L)

82
Q

Other name of salivary amylase

A

Ptyalin

83
Q

Other name of pancreatic amylase

A

Amylopsin

84
Q

2 types of amylase

A

Amylose
Amylopectin

85
Q

Breakdown from a-1,4 glycolysidic bonds produces

A

Glucose and maltose

86
Q

Breakdown from a-1,6 glycolysidic bonds produces

A

Dextrin

87
Q

Cellulose cannot be broken down by amylase bcs

A

B-1,4

88
Q

Enzymes used in continuous monitoring method

A

Amylasr
a-glucosidase
Hexokinase
G-6-PD

89
Q

Maltopentose + AMS =

A

Maltrotriose + maltose

90
Q

Maltrotriose + maltose + a-glucosidase

A

5-Glucose + 5 ATP

91
Q

5-Glucose + 5 ATP + Hexokinase

A

5-Glucose-6-phosphate + 5 ADP

92
Q

5-Glucose-6-phosphate + 5 NAD + G6PD

A

5,6-Phosphogluconolactone + 5 NADH

93
Q

Continuous Monitoring method is measured by using…

A

Spectrophotometry

94
Q

Tubes that can be used for AMS

A

Red
Gold
Green

95
Q

For AMS, and coupled enzyme method is nit used, is it okay to accept hemolyzed sample?

A

Yes

96
Q

AMS sample

A

Fresh serum/ plasma (free if hemolysis)
Urine (1/3 diluted)

97
Q

Alpha-Amylase Activity formula

A

(Change in absorbance/min.) x 3178

U/L

98
Q

Amylase reference range agappe

A

Serum/ plasma: 35-86 U/L
Urine: < 470 U/L

99
Q

Coenzyme of lipase

A

Colipase

100
Q

Rate of clearing is measured

LPS

A

Turbidimetric method

101
Q

Room temp

A

20-25C